JPH0789037B2 - Positioning device for moving objects - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an object positioning device for positioning a moving object. The present invention is particularly, but not exclusively, suitable for positioning and guiding missiles, such as anti-tank missiles.

A photodetector, e.g. a simple detector, working in conjunction with a light emitter, e.g. a light tracker, fixedly mounted and connected to the moving object, e.g. Devices with eyeglass sights are already known. Although fixedly mounted, the photodetector is adapted to orient in a particular direction,
It is therefore directed at the light emitter at each instant. As a result, the instant specific orientation of the photodetector with respect to the reference axis will represent the position of the missile with respect to this reference axis.

Therefore, such known positioners suffer from the disadvantage that the photodetectors must be continuously oriented in a particular direction to track the missile, which requires the operation of the missile's full flight range operator. there were. Further, the sensor must be equipped with a photodetector so that its orientation in a particular direction can generate an electrical signal representative of the position of the missile and can be used to guide it as well.

One so-called second generation weapon system ensures the positioning of the missile and its guidance with respect to the aiming axis defined by the firearm.

The coupling between the firing station and the missile is established between a detector aligned with the line of sight and a light source connected to the missile whose signature must have certain characteristics.

The characteristics of this signature are the radiation spectrum of the light source, the radiation force with respect to the parasitic signal corresponding to the background, the radiation frequency of the light source or the radiation phase of the light source.

Known positioning devices cannot simultaneously use all the cognitive criteria defined above.

The purpose of this invention is to overcome these drawbacks.

To this end, according to the invention, a photodetector is arranged which is fixedly arranged and is operated in conjunction with a light emitter which is connected to a moving object, for positioning said object in motion about one axis. Should be noted in the following points.

That is, the photodetector relates on the one hand to an optical system whose surface is at least substantially perpendicular to the axis and which is adapted to form a matrix image of the environment of the axis in which the moving object can move. It consists of a fixed matrix of controllable optoelectronic devices, and on the other hand an electronic control unit for controlling the optoelectronic devices. A light emitter produces a flashing signal and a synchronizing means is provided for said electronic control means for supplying a control pulse in synchronism with the flashing signal so as to capture an image.

In this way, the position of the object moving with respect to the axis is given by the position of each photoelectric element or each photoelectric element of the matrix activated by the image of the blinking signal with respect to the axis. Therefore, tracking of a moving object with a photodetector that can be oriented and a sensor related to the orientation of the photodetector is not necessary.

Moreover, a particularly high signal-to-noise ratio is obtained because the operating pulses of this device according to the invention are not continuous. In fact, thanks to the invention, this device is able to incorporate imaging whose period is equal to the period of the light source blinking and which is synchronized in frequency and phase with the light emission.

In this way, by synchronizing the detector source and the light source, the detector can operate at useful signal levels close to the peak emission power of the radiator.

Therefore, this combination can work with high signal-to-noise ratio for low average power, limiting light source wear and cost.

The optoelectronic device is advantageously a charge transfer device (generally abbreviated as CCD) in which the sampling output signal is particularly adapted for digital processing.

A light emitter that produces a blink signal and is connected to a moving object may be a simple mirror that receives the blink signal from a light beacon or a fixed beacon and returns the blink signal to the photodetector.

The synchronization between the photodetector and the light emitter can be obtained by permanent or temporary coupling means. In that case, the photodetector and the light emitter are individually provided with means (time base) for maintaining synchronization.

The blinking signal and thus the pulses controlling the electronic control unit for controlling the optoelectronic device are repeated periodically or according to any other desired law. However, in order to encode the frequency and phase of the link and protect against natural or artificial obstacles, the light emitters and photodetectors are triggered off in a random or pseudo-random manner.

The device according to the invention works with a high signal-to-noise ratio and makes it possible to limit the device to a simple treatment of the image provided by the matrix of photoelements, while being good against possible natural or artificial obstacles. Maintain a deactivated state.

In order to further improve the position information provided by the photodetector, additional temporary pulses that occur very closely before and / or after each of the temporary positioning pulses corresponding to the blinking are referenced under the same conditions synchronized with the blinking. The firing can be triggered off.

This device comprises means for comparing the information supplied by the matrix for one pair of positioning pulses with one additional pulse combined together. In this way, the additional pulse allows the reference image of the field in which the missile is moving to be established, and comparison of this information can eliminate possible parasitic sources in this field.

Also, such comparisons can more automatically compensate for photodetector deficiencies such as obscure levels, spatial noise, singularities, poor transfer, lack of uniform response, and the like.
It therefore reduces the detector quality requirements and allows it to operate at higher temperatures without gain compensation.

If the resulting blinks are temporarily identified,
The device according to the invention makes it possible to position several moving objects simultaneously. The device according to the invention thus enables angular displacement measurements of a plurality of moving objects to be carried out.

The present invention will be readily understood by reading the following description with reference to the accompanying drawings.

Next, examples will be described. The embodiment of the positioning device according to the invention shown in FIG. 1 is, for example, a continuous position of the missile 1 with respect to an axis OX representing the line of sight of an anti-tank weapon device (not shown) equipped with the positioning device. I am supposed to direct you.

The positioning device includes, for example, a photodetector 2 fixedly arranged in the weapon device, a light emitter or pulsed light beacon 3 mounted on the missile 1, a photodetector 2 and a rotary light beacon. It is essentially constituted by a synchronization link 4 which connects to 3.

The photodetector 2 essentially consists of a photoelectric element 6, for example a charge transfer device (CCD) type matrix 5, an optical system 7 and an electronic circuit 8 for using the matrix 5.

In the matrix 5, the photoelectric elements 6 are arranged in the same plane array of rows and columns. Each of them is axis OY and axis
It is parallel to OX. The point O is, for example, the center of the matrix 5. The axes OX, OY and OZ form an orthogonal axis system in which the axis OX is perpendicular to the plane of the matrix 5. On the other hand, axis OY and
OZ is coplanar with matrix 5.

The optical system 7 is capable of forming an image of the space surrounding the axis OX on the matrix 5.

The electronic circuit 8 can read out the charge generated by the optoelectronic device during the temporary pulse 9 (see FIG. 3b). That is, it can capture a continuous image of the space surrounding the axis OX. The exposure period of the matrix 5, that is, the period of the temporary pulse 9 and the period of the image shot are short, and correspond to the integration time of photons on the photosensitive band of the photoelectric element 6. It is on the order of 50 μS.

The pulse 9 is periodic, but the instants it appears are not necessarily temporally equidistant, so that the pulse appears according to a temporal law that differs from the periodic or random method.

The light beacon 3 comprises a pulse source capable of emitting a blinking pulse 10 of visible or infrared light. For example, the pulse source is a xenon lamp with focusing optics or a laser diode with a pulse generator or optics or a laser diode without optics.

The blinking pulse 10 has a short pulse width, for example, on the order of 20 μS.

The pulse source preferably comprises a filter of small spectral width which limits the emission of the light beacon 3. Similarly,
The same filter is associated with the optics 7 of the detector 2 to allow for the removal of radiation outside the emission band of the light beacon 3 and possibly the spectral separation that may be desired.

Flashing pulse by optical beacon 3 thanks to the sync link
The emission of 10 is synchronized with the image acquisition performed by the matrix 5 which is triggered off by the electronic circuit 8. This is shown in Figures 3a and 3b which show that the temporary pulse 9 is synchronized with the blinking pulse 10. Furthermore, the duration of each temporary pulse 9 is at least equal to the duration of the blinking pulse 10. Thus, each blinking pulse is temporarily completely covered by the temporary pulse 9.

The synchronization link 4 between the photodetector 2 and the optical beacon 3 may always be coupled, for example in the form of an extendable wire or a wireless or optical link. Also, the photodetector 2 and the optical beacon 3
Pulse 9 to capture the entire in-flight image of the missile
And a stable clock capable of maintaining the synchronization of the blinking pulse 10, the coupling between the detector 2 and the light beacon 3 may be temporary.

In this way, whenever a blinking pulse 10 is emitted by the light beacon 3, the photodetector 2 is activated as a result of the blinking pulse hitting at least one element 6 ′ of the matrix 5. Thus, the energized element 6'consists of the image of the blinking pulse 10 detected by the photodetector 2. Since the blinking pulse 10 is connected to the missile 1, the coordinates of the element 6'actuated with respect to the axis OY and the axis OZ are characteristic of the position of the missile with respect to the axis OX.

From the coordinates of the actuating element 6 ', the electronic circuit 8 produces a signal representative of the position, possibly for correcting the missile path.

FIG. 4 shows an embodiment of the device according to the invention. The light emitter 3 includes a time base 11 which supplies a sequencer 12. The sequencer 12 is a light source 14 which itself emits a flashing pulse 10.
The electronic trigger device 13 for controlling the The electronics that control the photodetector 2 include a time base 15 connected to a processing unit 16 which activates an image acquisition sequencer 17. The sequencer 17 controls the electronic device 18 for operating the matrix 5 and connected to the image memory 19. The interface 20 can ensure the synchronization between the light emitter 3 and the photodetector 2 via the synchronization link 4.

As shown in FIG. 5, a comparator 21 is placed between the electronic device 18 for operating the matrix 5 and the image memory 19. The operation of the device according to the invention is shown in FIG. FIG. 6 shows that each temporal pulse 9 for emitting a blinking pulse 10 is associated with a temporal pulse 22 for an acquisition which is offset with respect to the blinking pulse 10. In this way, the temporary pulse 22 for controlling the matrix 5 corresponds to a shot of the field in which the missile 1 is moving. As a result, the comparator 21 provides at its output a signal which simply corresponds to a blinking pulse 10. The background of the field is such that the image signal corresponding to the temporary pulse 22 is subtracted from the image signal corresponding to its associated temporary pulse 9.

Therefore, the signal stored in the image memory 19 after the temporary pulse 9 contains only information about the corresponding blinking pulse 10. Therefore, the positioning of the missile 1 is particularly accurate.

[Brief description of drawings]

1 is a schematic diagram of a positioning device according to the invention, FIG. 2 is a schematic diagram of a matrix of photoelectric elements used in the device of FIG. 1, and FIGS. 3a and 3b are diagrams of FIG. 1 as a function of time t. FIG. 4 is a block diagram of an embodiment of the device shown in FIG. 1, FIG. 5 is a block diagram of another embodiment of the device shown in FIG. 4, and FIGS. FIG. 9 is an operation explanatory diagram of another embodiment of FIG. 5 as a function. 1 ... Missile, 2 ... Photodetector, 3 ... Optical beacon,
4 ... Synchronous link, 5 ... Matrix, 6 ... Photoelectric element, 10 ... Blinking pulse, 11,15 ... Time base, 12,17
…… Sequencer, 13 …… Electronic trigger device, 14 …… Light source,
16 ... Processing device, 18 ... Electronic device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Jean-Pierre Merle France, 91400 Orsay, Are de Lore du Bois 12 (72) Inventor Jack Rose de Zoldon France, 91600 Savigny , Leu Chamberlin 25 (56) References US Patent 4449443 (US, A)

Claims (8)

[Claims] 1. A device for positioning an object in motion about one axis, a photoelectric detector associated with an optical system fixedly arranged to monitor the environment of the axis in which the object can move. And a light emitter connected to the moving object to generate a flashing signal, the photoelectric detector comprising a fixed matrix of controllable photoelectric elements on the one hand and for controlling the photoelectric elements on the other hand. 2. A device for positioning a moving object, characterized in that the electronic control means is provided with a synchronizing means for supplying a control pulse for triggering off the taking-in of an image in synchronism with the blinking signal. 2. Positioning device for a moving object according to claim 1, characterized in that the control pulse temporarily covers all of the blinking signals. 3. There are additional, temporally adjacent control pulses generated other than some blinking signals associated with each control pulse, said matrix being present during the duration of the control pulse and its associated additional control pulse. Device for positioning a moving object according to claim 1, characterized in that it comprises means for comparing the supplied electrical signals. 4. The apparatus for positioning a moving object according to claim 1, wherein the photoelectric element is a charge transfer type element. 5. Positioning device for a moving object according to claim 1, characterized in that the synchronization between the light emitter and the photodetector is always coupled. 6. The synchronization between the light emitter and the photodetector is obtained by a temporary coupling means, comprising means for maintaining the synchronization after breaking the temporary coupling. 5. A device for positioning a moving object according to claim 1. 7. The apparatus for positioning a moving object according to claim 1, wherein the blinking signal is periodic. 8. The apparatus for positioning a moving object according to claim 1, wherein the blinking signal is generated at a pseudo-random instant.